Concentrated surfactant compositions are desirable for a number of reasons. Concentrated surfactant compositions can be used neat, or they may be used to formulate other compositions, such as liquid laundry detergents. Concentrated compositions, with high levels of active ingredients, give the formulator flexibility. Lower levels of water can lead to lower transportation costs. Concentrated formulas may be useful in unitized dose compositions. Concentrated compositions may have a smaller ecological footprint as they use less packaging. However, concentrated compositions can lead to viscosity and stability challenges. For example, concentrated surfactant compositions may be too “thick” and lead to difficulties in processing or usage. Furthermore, at high concentrations, the composition may phase separate, or some surfactants may salt out. Therefore, there is a continuing need for improved concentrated surfactant compositions with good stability and desirable viscosity.
It is known that sulfated surfactants such as alkyl ethoxylated surfactants may be formulated at increased concentrations (e.g., 75% active or more) at somewhat acidic pHs (e.g., pH 5.5). The use of fatty acids has been taught to lower the pH and help to solubilize the sulfated surfactants. However, such compositions may remain relatively “thick” (e.g., viscosities of about 40 Pa*s at 1 s−1 or more) and can be challenging to transport, handle, or process. Furthermore, concentrated sulfated surfactant compositions can be chemically unstable at low pHs.
A need therefore exists for a stable concentrated surfactant composition that comprises an increased concentration of sulfated surfactant with desirable viscosity. The present disclosure meets this need by providing, in part, a stable, low pH, concentrated surfactant composition comprising sulfated surfactant and organic acid.